This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The termini of linear chromosomes are protected by telomeres, which are specialized DNA structures. Telemeres also facilitate the complete replication of DNA ends. The structure of resolvase and DNA will reveal how the formation of hairpin telomeres by protelomerase. We have crystallized protelomerase with different DNA substrate analogue. These complexes structures will show how the how the telomere structure is conserved. These will help us understand how the linear chromosomes integrity is preserved.